Circuit breaker



May 26, 1925. 1,539,451

- w. N. wlLLls CIRCUIT BREAKER FledJune 23, 192:5

Patented May 26, 1925.

UNITED STATES y 1,539,451 PATENT OFFICE.

WALTER N. WILLIS, OF EASTON, MARYLAND. ASSIGNOR F ONE-HALF TO GEORGEVJ.

HARDING, OF MERION, PENNSYLVANIA.

CIRCUIT BREAKER.

Application filed .Tune 23, 1923. Serial No. 647,250.

To a7] folio/11 if may confcrn Be it known that I, VALTER N. `W1 mis, a citizen of ,tie United States, residing at Easton, county of Talbot and State of Mary- 5 land, have invented a new and useful lmprovement in Circuit Breakers, of which thel following is a full, clear, and exact description, reference being had'to the accompanying drawings, which form a part of this specification.

My invention relates to circuit breakers, for example, ofthe type used in making and breaking high tension circuits in generating plants.

Heretofore it has been desired to provide a circuit breaker in which the movable contact rods Wo-uld travel in a true straight line in order that contact with the fixed contact points would be simultaneously made or broken, throughout the entire contact surface, with the avoidance of any tendency to arcing and consequent damaging results thereof, but such desideratum has not been accomplished truly or satisfactorily.

Thus, in the present form of circuit breakers, the contact rods either do not travel in an approximately true straight line, or, when an approximationA to true straight line travel is accomplished, the device is highly complicated, delicate, difficult to keep in adjustment and expensive to construct.

Now the object of my invention is to provide a circuit breaker in which the movable contact rods will travel in a true, strai ht line, thus insuring accurate and comp ete contact with the fixed contact points, and at the same time of great simplicity in construction and operation, with the result that 40 cost of construction is reduced to a minimum and the necessity for frequent adjustment is eliminated.

Having now indicated, in a general Way, the nature, purpose and advantage of my o invention, I will proceed to a detailed description of a preferred embodiment thereof, with reference to the accompanying drawings, in which- Fig. l is a side elevation of a device embodying my invention.

Fig. 2 is a cross-sectional view of the device illustrated in Fig. l.

a, a indicate cans, partially filled with oil, n which are positioned fixed contacts b.

c, c are movable contact rods, respectively positive and negative, adapted' to be moved vertically into and out of contact with the fixed contacts b, accordingly as it is desired to make or break the circuit.

d indicates a base plate, secured within a casing a: surrounding the circuit breaker, and supporting brackets placed one above the other and formed by two spaced apart plates e, e', having flanges f extending from the outer ends.

g, g indicate levers forked at their outer ends and pivotallysecured to the contact rodsc, c, as shown in Fig. 2. Adjacent the inner. ends, the levers are increased in size and an arcuate face g', formed with the pivotal connection between the levers and rods c, c as a center.

The levers g, g are supported between the bracket members e, e by means of pins 72 h, which pass through the levers and through longitudinally extending slots z' in the plates c, e forming the brackets.

The arcuate faces on the levers bear against the base plate d, forming fulcrums for the lever, and are held against the plate by means of springs j acting between the anges f on the bracket plates e, e and the pins h, h, the springs being guided by means of suitable guides carried by the flanges and pins as shown in Fig. 2. l

la indicates a hand lever pivoted at Z and provided with an arm m connected by means of a link n to an arm of one of the levers g and by which the contact rods c, c may be actuated. Spring catches o, o are provided for engaging the end of arm mor a projection p when the contact rods are in or out of Contact with the, fixed contacts b, b, in order that the contact rods may be retained in desired position.

It Will now appear that by virtue of the provision of the arcuate faces on the levers g g bearing upon the base plate d, fulcrums are provided for the levers which when the levers are rocked move or change position, due to the rolling of the arcuate faces on the base plate, causing the relative lengths of theA arms of the levers to be varied. The variation in the relative lengths of the arms of the levers compensates for the tendency of their ends to which the contact rods are pivoted to move in an arc, with the result that the contact rods are moved in a straight line. The pins 71, serve to support `the levers, sliding in the slots in the brackets as thel arcuate face rolls on the base.

It will be understood that I do not intend that my invention shall be limited to its application to circuit breakers, as it will be obvious that it may be adapted to a variety of other uses without departing from the spirit thereof. h a

Having now fully described my invention, what I claim and dcsireto protect by Letters Patent is:

l. The combination with a lever having a\` plurality of arms and an element connected with one of said arms, of a fulcruni therefor, the fnlcrum being movable to cause variation in the relative lengths of the arms of the lever.

2. In a circuit breaker, in combination, a movable contact, a fixed contact, a lever having a plurality of arms one of said arms being pivotally connected to said movable contact, and a fulcrum movable to cause variation in`the `relative length of the arms l of the lever.

3. In a circuit breaker, in combination a movable contact, a fixed contact, a lever having a plurality of arms one of said arms being pivotally connected to said movable contact, and a fulcrum for the lever movable in the operation of the lever to cause variation in the relative lengths of the arms of the lever.

4. In a circuit breaker, in combination, a movable contact, a fixed contact, a lever pivotally connected to said movable contact and provided at one end with an arcuate surface, means affording a plain surface adapted to provide a bearing for the arcuate end of said lever, and a movable fulcrum for said lever.

5. In a circuit breaker, in combination, a movable contact, a fixed contact, a lever pivotally connected to said movable contact and provided at one end with an arcuate surface, means affording a4 plain surface adapted to provide a bearing for the arcuate end of said lever, and means to rock said lever.

6. In a circuit breaker, in combination` a movable contact, a fixed contact, a lever pivotally connected to said movable contact,

a movable fulcrnm for said lever, and means "having an arcuate face at one end and pivotally connected to said contact at the other end, a base against which the arcuate end face of said lever is adapted to bear, a fulcrum for said lever movable in a direction transversc to its axis, andv means to rock said lever on said fulcrum.

9. In a circuit breaker, in combination, a fixed contact, a movable contact, av lever pivotally secured at one end to said movable contact and having its opposite end formed arcuate with the pivotal. connect-ion with the movable contact as a center, a movable fulcrum for the lever, and means to rock said lever whereby said movable contact will be moved toward and away from said fixed contact on a straight line.

10. In a circuit breaker, in combination, a pair of fixed contacts, a pair of movable contact rods, levers forked at one end, and having an arcuate face at the other end, the forked ends of said levers being pivotally secured to said contact rods, base plates against which tlie arcuate faces of said levers are adapted to bear, brackets provided with longitudinally extending slots, pins extending through said levers adjacent their arcuate faced ends and through the slots in said brackets, and springs extending between said brackets and said pins, adapted to tend to hold the arcuate faced ends of said levers against said base plates.

In testimony of which invention I have hereunto set my hand at Easton, Md., on this 11th day of May, 1923.

WALTER N. WILLIS.

' Certificate of Correction.

It is hereby certified that Letters Patent No. 1,539,451, granted 'May 2e, 1925,

upon the a plication of Walter N. Willis, of Easton, Maryland, for an im rovement in ircuit Breakers, were erroneously issued to the inventor, said aus,

and one-half to George J. Harding, of Merion, Pennsylvania, Whereasl said Letters Patent should have been issuedto the inventor, said Wz'lh'a, and one-Haard to George J. Harding, of Marion., Pennsylvania, as shown by the recordsof assignments. in 'this office; and that the' said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of July, A.

[SEAL] A W'M. A. KINNAN, Acting 00m/missione?" 0f Patents. 

